Mysql系列六：（Mycat分片路由原理、Mycat常用分片规则及对应源码介绍）_非关系型数据库

概述一、Mycat分片路由原理我们先来看下面的一个SQL在Mycat里面是如何执行的：select * from travelrecord where id in(5000001, 10000001);有3个分片dn1,dn2,dn3, id=5000001这条数据在dn2上，id=10000001这条数据在dn3上。查询时可能有出现的问题：1）全部扫描一遍dn1 dn2 dn3，结果导致性能浪费。2）只扫描某个片。漏掉数据的情况。总结：不能多扫——>性能不足也不能少——>漏掉数据那么Mycat是如何解决上面的问题的呢？Mycat使用Druid的DruidParser作为分析器/解析器，解析的过程主要有Visitor和Statement两个阶段说明：1）Visitor过程，解析出如下属性：哪一张表字段列表条件信息什么样的SQL解析出以上信息以后就可以根据schema.xml和rule.xml文件确认要去哪个分片上进行DML *** 作了2）Statement过程转化：转化后知道执行的是什么样的SQL（增删改查）3）改写SQL通过查询条件可以知道要查询的数据都在哪些分片上Dn2， id= 5000001Dn3， id= 100000001所以SQL被改写成以下的形式：select * from travelrecord where id = 5000001；（dn2执行）select * from travelrecord where id = 10000001；（dn3执行）4）分别在分片dn2，dn3上执行第 3）步改写的SQL，然后把从dn2，dn3上得到的结果进行拼装就是最终的结果了备注：多表关联查询的时候，visitor会遍历出所有的表，然后去各个分片上去获取结果，同时把结果缓存起来，最后根据关联查询计算出结果。确定分片的过程：首先看where条件里面是否含有分片字段，有就根据分片字段的值结合schema.xml、rule.xml的值确定是哪个分片。当不能确定在哪一个分片上的时候，mycat会到所有的分片上去找二、Mycat常用分片规则1. 时间类：按天分片、自然月分片、单月小时分片2. 哈希类：Hash固定分片、日期范围Hash分片、截取数字Hash求模范围分片、截取数字Hash分片、一致性Hash分片3. 取模类：取模分片、取模范围分片、范围求模分片4. 其他类：枚举分片、范围约定分片、应用指定分片、冷热数据分片下面基于源码来介绍Mycat的常用分片规则，源码地址三、Mycat常用分片规则介绍说明：分片规则都定义在rule.xml文件里面<tableRule name="rule1"><rule><columns>id</columns><algorithm>func1</algorithm></rule></tableRule><function name="func1" class="io.mycat.route.function.PartitionByLong"><property name="partitionCount">1,1,2,3,1</property><property name="partitionLength">128,128,128,128,128</property></function>1. 自动范围分片在rule.xml里面的配置：<tableRule name="auto-sharding-long"><rule><columns>id</columns><algorithm>rang-long</algorithm></rule></tableRule><function name="rang-long"class="io.mycat.route.function.AutoPartitionByLong"><property name="mapFile">autopartition-long.txt</property></function>说明：有3个分片，第1个分片存储的是1-500000的数据，第2个分片存储的是500001-1000000的数据，第3个分片存储的是1000001-1500000的数据insert into employee(id, name) value(1,Tom);在第1个分片insert into employee(id, name) value(500002,Jack);在第2个分片insert into employee(id, name) value(1000002,Lucy);在第3个分片对应代码：package io.mycat.route.function;import java.io.BufferedReader;import java.io.InputStream;import java.io.InputStreamReader;import java.util.HashSet;import java.util.LinkedList;import java.util.Set;import io.mycat.config.model.rule.RuleAlgorithm;/*** auto partition by Long ,can be used in auto increment primary key partition** @author wuzhi*/public class AutoPartitionByLong extends AbstractPartitionAlgorithm implements RuleAlgorithm{private String mapFile;private LongRange[] longRongs;private int defaultNode = -1;@Overridepublic void init() {initialize();}public void setMapFile(String mapFile) {this.mapFile = mapFile;}@Overridepublic Integer calculate(String columnValue) {// columnValue = NumberParseUtil.eliminateQoute(columnValue);try {long value = Long.parseLong(columnValue);Integer rst = null;for (LongRange longRang : this.longRongs) {if (value <= longRang.valueEnd && value >= longRang.valueStart) {return longRang.nodeIndx;}}//数据超过范围，暂时使用配置的默认节点if (rst == null && defaultNode >= 0) {return defaultNode;}return rst;} catch (NumberFormatException e){throw new IllegalArgumentException(new StringBuilder().append("columnValue:").append(columnValue).append(" Please eliminate any quote and non number within it.").toString(),e);}}@Overridepublic Integer[] calculateRange(String beginValue, String endValue) {return AbstractPartitionAlgorithm.calculateSequenceRange(this, beginValue, endValue);}@Overridepublic int getPartitionNum() {// int nPartition = longRongs.length;/** fix #1284 这里的统计应该统计Range的nodeIndex的distinct总数*/Set<Integer> distNodeIdxSet = new HashSet<Integer>();for(LongRange range : longRongs) {distNodeIdxSet.add(range.nodeIndx);}int nPartition = distNodeIdxSet.size();return nPartition;}private void initialize() {BufferedReader in = null;try {// FileInputStream fin = new FileInputStream(new File(fileMapPath));InputStream fin = this.getClass().getClassLoader().getResourceAsStream(mapFile);if (fin == null) {throw new RuntimeException("can't find class resource file "+ mapFile);}in = new BufferedReader(new InputStreamReader(fin));LinkedList<LongRange> longRangeList = new LinkedList<LongRange>();for (String line = null; (line = in.readLine()) != null;) {line = line.trim();if (line.startsWith("#") || line.startsWith("//")) {continue;}int ind = line.indexOf('=');if (ind < 0) {System.out.println(" warn: bad line int " + mapFile + " :"+ line);continue;}String pairs[] = line.substring(0, ind).trim().split("-");long longStart = NumberParseUtil.parseLong(pairs[0].trim());long longEnd = NumberParseUtil.parseLong(pairs[1].trim());int nodeId = Integer.parseInt(line.substring(ind + 1).tri 一、Mycat分片路由原理

我们先来看下面的一个sql在Mycat里面是如何执行的：

travelrecord ID (,);

有3个分片dn1,dn2,dn3,ID=5000001

dn1 dn2 dn3

2）只扫描某个片。漏掉数据的情况。

@H_301_40@

那么Mycat是如何解决上面的问题的呢？

Mycat解析的过程主要有Visitor和Statement两个阶段

1）Visitor过程，解析出如下属性：

　　　　　　　　　　　　　　哪一张表

　　　　　　　　　　　　　　字段列表

　　　　　　　　　　　　　　条件信息

　　　　　　　　　　　　　　什么样的sql

通过查询条件可以知道要查询的数据都在哪些分片上

travelrecord ID travelrecord ID ；（dn3执行）

4）分别在分片dn2，dn3上执行第 3）步改写的sql，然后把从dn2，dn3上得到的结果进行拼装就是最终的结果了

visitor

where

二、Mycat常用分片规则

1. 时间类：按天分片、自然月分片、单月小时分片

2. 哈希类：Hash固定分片、日期范围Hash分片、截取数字Hash求模范围分片、截取数字Hash分片、一致性Hash分片

3. 取模类：取模分片、取模范围分片、范围求模分片

4. 其他类：枚举分片、范围约定分片、应用指定分片、冷热数据分片

下面基于源码来介绍Mycat的常用分片规则，href="https://github.com/MyCATApache/Mycat-Server" target="_blank">源码地址

三、Mycat常用分片规则介绍

分片规则都定义在rule.xml文件里面

ID func1 1,1,2,3,1 128,128,128 1. 自动范围分片

在rule.xml里面的配置：

ID rang-long

<function name="rang-long"
class="io.mycat.route.function.AutopartitionByLong">
<property name="mapfile">autopartition-long.txt</property>
</function>

有3个分片，第1个分片存储的是1-500000的数据，第2个分片存储的是500001-1000000的数据，第3个分片存储的是1000001-1500000的数据

insert into employee(ID,name) value(1,Tom);在第1个分片

insert into employee(ID,name) value(500002,Jack);在第2个分片

insert into employee(ID,name) value(1000002,Lucy);在第3个分片

对应代码：

import java.io.BufferedReader;
import java.io.inputStream;
import java.io.inputStreamReader;
import java.util.HashSet;
import java.util.linkedList;
import java.util.Set;

import io.mycat.config.model.rule.RuleAlgorithm;

/**

auto partition by Long,can be used in auto increment primary key partition

@author wuzhi
*/
public class AutopartitionByLong extends AbstractPartitionAlgorithm implements RuleAlgorithm{

private String mapfile;
private LongRange[] longRongs;

private int defaultNode = -1;
@OverrIDe
public voID init() {

 initia<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ze();

}

public voID setMapfile(String mapfile) {
this.mapfile = mapfile;
}

@OverrIDe
public Integer calculate(String columnValue) {
// columnValue = NumberParseUtil.eliminateQoute(columnValue);
try {
long value = Long.parseLong(columnValue);
Integer rst = null;
for (LongRange longRang : this.longRongs) {
if (value <= longRang.valueEnd && value >= longRang.valueStart) {
return longRang.nodeIndx;
}
}
//数据超过范围，暂时使用配置的默认节点
if (rst == null && defaultNode >= 0) {
return defaultNode;
}
return rst;
} catch (NumberFormatException e){
throw new IllegalArgumentException(new StringBuilder().append("columnValue:").append(columnValue).append(" Please eliminate any quote and non number within it.").toString(),e);
}
}

@OverrIDe
public Integer[] calculaterange(String beginValue,String endValue) {
return AbstractPartitionAlgorithm.calculateSequenceRange(this,beginValue,endValue);
}

@OverrIDe
public int getPartitionNum() {
// int nPartition = longRongs.length;

 <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;/*</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;  * fix #1284 <a href="https://m.jb51.cc/tag/zheli/" target="_blank" >这里</a>的<a href="https://www.jb51.cc/tag/tongji/" target="_blank" >统计</a>应该<a href="https://www.jb51.cc/tag/tongji/" target="_blank" >统计</a>Range的nodeIndex的<a href="https://www.jb51.cc/tag/dis/" target="_blank" >dis</a>tinct总数  </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;*/</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; Set</span><Integer> <a href="https://www.jb51.cc/tag/dis/" target="_blank" >dis</a>tNode<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>xSet = <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> HashSet<Integer><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;(); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;(LongRange range : longRongs) {     <a href="https://www.jb51.cc/tag/dis/" target="_blank" >dis</a>tNode<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>xSet.add(range.nodeIndx); } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> nPartition =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://www.jb51.cc/tag/dis/" target="_blank" >dis</a>tNode<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>xSet.size(); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; nPartition;

}

private voID initialize() {
BufferedReader in = null;
try {
// fileinputStream fin = new fileinputStream(new file(fileMapPath));
inputStream fin = this.getClass().getClassLoader()
.getResourceAsstream(mapfile);
if (fin == null) {
throw new RuntimeException("can't find class resource file "
+ mapfile);
}
in = new BufferedReader(new inputStreamReader(fin));
linkedList longRangeList = new linkedList();

     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span> (String <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne = <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span>; (<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne = in.read<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne()) != <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;) {         <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne </span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.trim();         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.startsWith("#") || <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.startsWith("//"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)) {             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;continue</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         }         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> ind = <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.indexOf('='<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;);         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (ind < 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;) {             Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(</span>" warn: bad <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne int " + map<a href="https://m.jb51.cc/tag/file/" target="_blank" >file</a> + " :"                     +<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne);             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;continue</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         }             String pa<a href="https://www.jb51.cc/tag/irs/" target="_blank" >irs</a>[] </span>= <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.substring(0,ind).trim().sp<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>t("-"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;);             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> longStart = NumberParseUtil.parseLong(pa<a href="https://www.jb51.cc/tag/irs/" target="_blank" >irs</a>[0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;].trim());             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> longEnd = NumberParseUtil.parseLong(pa<a href="https://www.jb51.cc/tag/irs/" target="_blank" >irs</a>[1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;].trim());             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> node<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a> = Integer.parseInt(<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.substring(ind + 1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)                     .trim());             longRange<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>                     .add(</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; LongRange(node<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>,longStart,longEnd));     }     longRongs </span>= longRange<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>.toArray(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; LongRange[longRange<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>             .size()]); } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (Exception e) {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (e <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;instanceof</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; RuntimeException) {         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (RuntimeException) e;     } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; RuntimeException(e);     } } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;finally</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;try</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {         in.close();     } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (Exception e2) {     } }

}

public int getDefaultNode() {
return defaultNode;
}

public voID setDefaultNode(int defaultNode) {
this.defaultNode = defaultNode;
}

static class LongRange {
public final int nodeIndx;
public final long valueStart;
public final long valueEnd;

 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;pub<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>c</span> LongRange(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> nodeIndx,<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> valueStart,<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; valueEnd) {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;super</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;();     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span>.nodeIndx =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; nodeIndx;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span>.valueStart =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; valueStart;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span>.valueEnd =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; valueEnd; }

}
}

2. 枚举分片

把数据分类存储

在rule.xml里面的配置：

sharding_ID hash-int partition-hash-int.txt 0

对应代码：

import java.io.BufferedReader;
import java.io.inputStream;
import java.io.inputStreamReader;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import io.mycat.config.model.rule.RuleAlgorithm;

/**

@author mycat
*/
public class PartitionByfileMap extends AbstractPartitionAlgorithm implements RuleAlgorithm {

private String mapfile;
private Map<Object,Integer> app2Partition;
/**

Map<Object,Integer> app2Partition中key值的类型：默认值为0，0表示Integer，非零表示String
*/
private int type;

/**

默认节点在map中的key
*/
private static final String DEFAulT_NODE = "DEFAulT_NODE";

/**

默认节点:小于0表示不设置默认节点，大于等于0表示设置默认节点默认节点的作用：枚举分片时，如果碰到不识别的枚举值，就让它路由到默认节点如果不配置默认节点（defaultNode值小于0表示不配置默认节点），碰到不识别的枚举值就会报错，like this：can't find datanode for sharding column:column_name val:ffffffff
*/
private int defaultNode = -1;

@OverrIDe
public voID init() {

 initia<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ze();

}

public voID setMapfile(String mapfile) {
this.mapfile = mapfile;
}

public voID setType(int type) {
this.type = type;
}

public voID setDefaultNode(int defaultNode) {
this.defaultNode = defaultNode;
}

@OverrIDe
public Integer calculate(String columnValue) {
try {
Object value = columnValue;
if (type == 0) {
value = Integer.valueOf(columnValue);
}
Integer rst = null;
Integer pID = app2Partition.get(value);
if (pID != null) {
rst = pID;
} else {
rst = app2Partition.get(DEFAulT_NODE);
}
return rst;
} catch (NumberFormatException e){
throw new IllegalArgumentException(new StringBuilder().append("columnValue:").append(columnValue).append(" Please check if the format satisfIEd.").toString(),e);
}
}

@OverrIDe
public int getPartitionNum() {
Set set = new HashSet(app2Partition.values());
int count = set.size();
return count;
}

     app2Partition </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> HashMap<Object,Integer><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;();     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span> (String <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne = <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span>; (<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne = in.read<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne()) != <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;) {         <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne </span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.trim();         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.startsWith("#") || <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.startsWith("//"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)) {             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;continue</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         }         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> ind = <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.indexOf('='<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;);         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (ind < 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;) {             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;continue</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         }         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;try</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {             String key </span>= <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.substring(0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;,ind).trim();             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> p<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a> = Integer.parseInt(<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.substring(ind + 1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;).trim());             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span>(type == 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;) {                 app2Partition.put(Integer.parseInt(key),p<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>);             } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {                 app2Partition.put(key,p<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>);             }         } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (Exception e) {         }     }     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;//</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;<a href="https://m.jb51.cc/tag/shezhi/" target="_blank" >设置</a><a href="https://www.jb51.cc/tag/mo/" target="_blank" >默</a>认节点</span>     <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span>(defa<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>tNode >= 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;) {         app2Partition.put(DEFA<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>T_NODE,defa<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>tNode);     } } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (Exception e) {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (e <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;instanceof</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; RuntimeException) {         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (RuntimeException) e;     } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; RuntimeException(e);     } } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;finally</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;try</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {         in.close();     } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (Exception e2) {     } }

}
}

3. Hash固定分片（固定分片Hash算法）

Hash

在rule.xml里面的配置：

ID func1 1,128

1) partitionCount.length

2) sum((partitionCount[i]*partitionLength[j])) === 1024——>partitionCount[0]*partitionLength[0]+partitionCount[1]*partitionLength[1] === 1024

1*128+1*128+2*128+3*128+1*128 === 1024

eg：

...................

ID%1024 = 128

import io.mycat.config.model.rule.RuleAlgorithm;
import io.mycat.route.util.PartitionUtil;

public final class PartitionByLong extends AbstractPartitionAlgorithm implements RuleAlgorithm {
protected int[] count;
protected int[] length;
protected PartitionUtil partitionUtil;

</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;private</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;static</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;[] toIntArray(String string) {    String[] strs </span>= io.mycat.util.Sp<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>tUtil.sp<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>t(string,',<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;true</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;);    </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span>[] ints = <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;[strs.length];    </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span> (<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> i = 0; i < strs.length; ++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;i) {        ints[i] </span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; Integer.parseInt(strs[i]);    }    </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; ints;}</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;pub<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>c</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;vo<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a></span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; setPartitionCount(String partitionCount) {    </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span>.count =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; toIntArray(partitionCount);}</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;pub<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>c</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;vo<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a></span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; setPartitionLength(String partitionLength) {    </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span>.length =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; toIntArray(partitionLength);}@Overr<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>e</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;pub<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>c</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;vo<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a></span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; init() {    partitionUtil </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; PartitionUtil(count,length);}@Overr<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>e</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;pub<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>c</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; Integer cal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>te(String c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue)  {

// columnValue = NumberParseUtil.eliminateQoute(columnValue);
try {
long key = Long.parseLong(columnValue);
return partitionUtil.partition(key);
} catch (NumberFormatException e){
throw new IllegalArgumentException(new StringBuilder().append("columnValue:").append(columnValue).append(" Please eliminate any quote and non number within it.").toString(),endValue);
}

// @OverrIDe
// public int getPartitionCount() {
// int nPartition = 0;
// for(int i = 0; i < count.length; i++) {
// nPartition += count[i];
// }
// return nPartition;
// }

}

4. 求模分片

ID%

在rule.xml里面的配置：

ID mod-long 3

对应代码：

import java.math.BigInteger;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import io.mycat.config.model.rule.RuleAlgorithm;

/**

number column partion by Mod operator

if count is 10 then 0 to 0,21 to 1 (21 % 10 =1)

@author wuzhih

*/
public class PartitionByMod extends AbstractPartitionAlgorithm implements RuleAlgorithm {

private int count;
@OverrIDe
public voID init() {

}

public voID setCount(int count) {
this.count = count;
}

@OverrIDe
public Integer calculate(String columnValue) {
// columnValue = NumberParseUtil.eliminateQoute(columnValue);
try {
BigInteger bigNum = new BigInteger(columnValue).abs();
return (bigNum.mod(BigInteger.valueOf(count))).intValue();
} catch (NumberFormatException e){
throw new IllegalArgumentException(new StringBuilder().append("columnValue:").append(columnValue).append(" Please eliminate any quote and non number within it.").toString(),e);
}

}

@OverrIDe
public int getPartitionNum() {
int nPartition = this.count;
return nPartition;
}

private static voID hashtest() {
PartitionByMod hash=new PartitionByMod();
hash.setCount(11);
hash.init();

 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span>[] bucket=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;[hash.count]; Map</span><Integer,<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a><Integer>> hashed=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> HashMap<><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;(); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> total=1000_0000;<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;//</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;数据量</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> c=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> i=100_0000;i<total+100_0000;i++){<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;//</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;假设分片键从100万开始</span>     c++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> h=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;hash.cal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>te(Integer.toString(i));     bucket[h]</span>++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a></span><Integer> <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;hashed.get(h);     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span>(<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>==<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;){         <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a></span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Array<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a><><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;();         hashed.put(h,<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>);     }     <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>.add(i); } Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(c</span>+"   "+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;total); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;double</span> d=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; c</span>=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> <a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>x=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(</span>"index    bucket   ratio"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; i:bucket){     d</span>+=i/(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;double</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)total;     c</span>+=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;i;     Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>x</span>+++"  "+i+"   "+(i/(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;double</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)total)); } Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(d</span>+"  "+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;c); Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(</span>"****************************************************"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;); rehashTest(hashed.get(</span>0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;));

}
private static voID rehashTest(List partition) {
PartitionByMod hash=new PartitionByMod();
hash.count=110;//分片数
 hash.init();

 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span>[] bucket=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;[hash.count]; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> total=partition.size();<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;//</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;数据量</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> c=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> i:partition){<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;//</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;假设分片键从100万开始</span>     c++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> h=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;hash.cal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>te(Integer.toString(i));     bucket[h]</span>++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; } Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(c</span>+"   "+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;total); c</span>=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> <a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>x=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(</span>"index    bucket   ratio"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; i:bucket){     c</span>+=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;i;     Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>x</span>+++"  "+i+"   "+(i/(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;double</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)total)); }

}
public static voID main(String[] args) {
// hashtest();
PartitionByMod partitionByMod = new PartitionByMod();
partitionByMod.count=8;
partitionByMod.calculate("\"6\"");
partitionByMod.calculate("\'6\'");
}
}

5. 自然月分片

按照自然月的方式进行分片

在rule.xml里面的配置：

create_time partbymonth yyyy-MM-dd 2015-01-01

sEndDated

分片

对应代码：

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.List;

import io.mycat.config.model.rule.RuleAlgorithm;
import org.apache.log4j.Logger;

/**

例子按月份列分区，每个自然月一个分片，格式 between *** 作解析的范例

@author wzh

*/
public class PartitionByMonth extends AbstractPartitionAlgorithm implements
RuleAlgorithm {
private static final Logger LOGGER = Logger.getLogger(PartitionByDate.class);
private String sBeginDate;
private String dateFormat;
private String sEndDate;
private Calendar beginDate;
private Calendar endDate;
private int nPartition;

private ThreadLocal formatter;

@OverrIDe
public voID init() {
try {
beginDate = Calendar.getInstance();
beginDate.setTime(new SimpleDateFormat(dateFormat)
.parse(sBeginDate));
formatter = new ThreadLocal() {
@OverrIDe
protected SimpleDateFormat initialValue() {
return new SimpleDateFormat(dateFormat);
}
};
if(sEndDate!=null&&!sEndDate.equals("")) {
endDate = Calendar.getInstance();
endDate.setTime(new SimpleDateFormat(dateFormat).parse(sEndDate));
nPartition = ((endDate.get(Calendar.YEAR) - beginDate.get(Calendar.YEAR)) * 12

endDate.get(Calendar.MONTH) - beginDate.get(Calendar.MONTH)) + 1;

         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (nPartition <= 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;) {             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> <a href="https://www.jb51.cc/tag/javalang/" target="_blank" >java.lang</a>.Ille<a href="https://www.jb51.cc/tag/gal/" target="_blank" >gal</a>ArgumentException("Incorrect time range for month partitioning!"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;);         }     } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {         nPartition </span>= -1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     } } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (ParseException e) {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://www.jb51.cc/tag/javalang/" target="_blank" >java.lang</a>.Ille<a href="https://www.jb51.cc/tag/gal/" target="_blank" >gal</a>ArgumentException(e); }

}

/**

For circulatory partition,calculated value of target partition needs to be

rotated to fit the partition range
*/
private int reCalculatePartition(int targetPartition) {
/**

If target date is prevIoUs of start time of partition setting,shiftthe delta range between target and start date to be positive value
*/
if (targetPartition < 0) {
targetPartition = nPartition - (-targetPartition) % nPartition;
}

if (targetPartition >= nPartition) {
targetPartition = targetPartition % nPartition;
}

return targetPartition;
}

@OverrIDe
public Integer calculate(String columnValue) {
try {
int targetPartition;
Calendar curTime = Calendar.getInstance();
curTime.setTime(formatter.get().parse(columnValue));
targetPartition = ((curTime.get(Calendar.YEAR) - beginDate.get(Calendar.YEAR))
* 12 + curTime.get(Calendar.MONTH)
- beginDate.get(Calendar.MONTH));

     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;/**</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;      * For cir<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>tory partition,cal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>ted value of target partition needs to be      * rotated to fit the partition range       </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;*/</span>     <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (nPartition > 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;) {         targetPartition </span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; reCal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>tePartition(targetPartition);     }     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; targetPartition; } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (ParseException e) {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Ille<a href="https://www.jb51.cc/tag/gal/" target="_blank" >gal</a>ArgumentException(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> StringBuilder().append("c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue:").append(c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue).append(" Please check if the format satisf<a href="https://m.jb51.cc/tag/IE/" target="_blank" >IE</a>d."<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;).toString(),e); }

}

@OverrIDe
public Integer[] calculaterange(String beginValue,String endValue) {
try {
int startPartition,endPartition;
Calendar partitionTime = Calendar.getInstance();
SimpleDateFormat format = new SimpleDateFormat(dateFormat);
partitionTime.setTime(format.parse(beginValue));
startPartition = ((partitionTime.get(Calendar.YEAR) - beginDate.get(Calendar.YEAR))
12 + partitionTime.get(Calendar.MONTH)
- beginDate.get(Calendar.MONTH));
partitionTime.setTime(format.parse(endValue));
endPartition = ((partitionTime.get(Calendar.YEAR) - beginDate.get(Calendar.YEAR))
12 + partitionTime.get(Calendar.MONTH)
- beginDate.get(Calendar.MONTH));

     <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a></span><Integer> <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a> = <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Array<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a><><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;();     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;while</span> (startPartition <=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; endPartition) {         Integer nodeValue </span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; reCal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>tePartition(startPartition);         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (C<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>lections.frequency(<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>,nodeValue) < 1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)             <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>.add(nodeValue);         startPartition</span>++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     }     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> size =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>.size();     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span> (<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>.toArray(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; Integer[size])); } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (ParseException e) {     LOGGER.error(</span>"error"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;,e);     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Integer[0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;]; }

}

@OverrIDe
public int getPartitionNum() {
int nPartition = this.nPartition;
return nPartition;
}

public voID setsBeginDate(String sBeginDate) {
this.sBeginDate = sBeginDate;
}

public voID setDateFormat(String dateFormat) {
this.dateFormat = dateFormat;
}

public voID setsEndDate(String sEndDate) {
this.sEndDate = sEndDate;
}

}

6. 匹配求模分片

prefixLengthcharat(i)

在rule.xml里面的配置：

ID partitionbyprefixpattern 3 6

有下面这种类型的数据

201801 01 10001

columns6

对应代码：

import io.mycat.config.model.rule.RuleAlgorithm;
import io.mycat.route.function.AutopartitionByLong.LongRange;

/**

partition by Prefix length,can be used in String partition

@author hexiaobin
*/
public class PartitionByPrefixPattern extends AbstractPartitionAlgorithm implements RuleAlgorithm {
private static final int PARTITION_LENGTH = 1024;
private int patternValue = PARTITION_LENGTH;// 分区长度，取模数值(默认为1024)
private int prefixLength;// 字符前几位进行ASCII码取和
private String mapfile;
private LongRange[] longRongs;

@OverrIDe
public voID init() {

 initia<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ze();

}

public voID setMapfile(String mapfile) {
this.mapfile = mapfile;
}

public voID setPatternValue(int patternValue) {
this.patternValue = patternValue;
}

public voID setPrefixLength(int prefixLength) {
this.prefixLength = prefixLength;
}

@OverrIDe
public Integer calculate(String columnValue) {
try {
int Length = Integer.valueOf(prefixLength);

     Length </span>= c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue.length() < Length ?<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue.length() : Length;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> sum = 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span> (<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> i = 0; i < Length; i++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;) {         sum </span>= sum +<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue.ch<a href="https://www.jb51.cc/tag/ara/" target="_blank" >ara</a>t(i);     }     Integer rst </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span> (LongRange longRang : <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;.longRongs) {         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> hash = sum %<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; patternValue;         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (hash <= longRang.valueEnd &amp;&amp; hash >=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; longRang.valueStart) {             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; longRang.nodeIndx;         }     }     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; rst; } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (NumberFormatException e){     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Ille<a href="https://www.jb51.cc/tag/gal/" target="_blank" >gal</a>ArgumentException(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> StringBuilder().append("c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue:").append(c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue).append(" Please e<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>minate any quote and non number within it."<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;).toString(),e); }

}

@OverrIDe
public int getPartitionNum() {
// int nPartition = this.longRongs.length;
/*

fix #1284 这里的统计应该统计Range的nodeIndex的distinct总数
*/
Set distNodeIDxSet = new HashSet();
for(LongRange range : longRongs) {
distNodeIDxSet.add(range.nodeIndx);
}
int nPartition = distNodeIDxSet.size();
return nPartition;
}

     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span> (String <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne = <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span>; (<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne = in.read<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne()) != <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;) {         <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne </span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.trim();         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.startsWith("#") || <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.startsWith("//"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)) {             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;continue</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         }         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> ind = <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.indexOf('='<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;);         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (ind < 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;) {             Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(</span>" warn: bad <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne int " + map<a href="https://m.jb51.cc/tag/file/" target="_blank" >file</a> + " :"                     +<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne);             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;continue</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         }             String pa<a href="https://www.jb51.cc/tag/irs/" target="_blank" >irs</a>[] </span>= <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>ne.substring(0,longEnd));     }     longRongs </span>= longRange<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>.toArray(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; LongRange[longRange<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>             .size()]); } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (Exception e) {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (e <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;instanceof</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; RuntimeException) {         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (RuntimeException) e;     } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; RuntimeException(e);     } } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;finally</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;try</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {         in.close();     } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (Exception e2) {     } }

}

 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;pub<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>c</span> LongRange(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> nodeIndx,<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; valueEnd) {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;super</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;();     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span>.nodeIndx =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; nodeIndx;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span>.valueStart =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; valueStart;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span>.valueEnd =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; valueEnd; }

}
}

7. 冷热数据分片

根据日期查询日志数据冷热数据分布，最近 n 个月的到实时交易库查询，超过 n 个月的按照 m 天分片。

在rule.xml里面的配置：

create_time sharding-by-hotdate

对应代码：

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.mycat.config.model.rule.RuleAlgorithm;

/**

根据日期查询日志数据冷热数据分布，最近n个月的到实时交易库查询，超过n个月的按照m天分片

@author sw

create_time sharding-by-hotdate PartitionByHotDate AbstractPartitionAlgorithm Logger LOGGER = LoggerFactory.getLogger(PartitionByHotDate.private String dateFormat;
private String sLastDay;
private String sPartionDay;

private long sLastTime;
private long partionTime;
private ThreadLocal formatter;

private long beginDate;

private static final long oneDay = 86400000;

@OverrIDe
public voID init() {
try {
formatter = new ThreadLocal() {
@OverrIDe
protected SimpleDateFormat initialValue() {
return new SimpleDateFormat(dateFormat);
}
};
sLastTime = Integer.valueOf(sLastDay);
partionTime = Integer.parseInt(sPartionDay) * oneDay;
} catch (Exception e) {
throw new java.lang.IllegalArgumentException(e);
}
}

@OverrIDe
public Integer calculate(String columnValue) {
Integer targetPartition = -1;
try {
long targetTime = formatter.get().parse(columnValue).getTime();
Calendar Now = Calendar.getInstance();
long NowTime = Now.getTimeInMillis();

     beginDate </span>= <a href="https://www.jb51.cc/tag/Now/" target="_blank" >Now</a>Time - sLastTime *<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; oneDay;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> diffDays = (<a href="https://www.jb51.cc/tag/Now/" target="_blank" >Now</a>Time - targetTime) / (1000 * 60 * 60 * 24) + 1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span>(diffDays-sLastTime <= 0 || diffDays<0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; ){         targetPartition </span>= 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     }</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;{         targetPartition </span>= (<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span>) ((beginDate - targetTime) / partionTime) + 1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     }     LOGGER.de<a href="https://m.jb51.cc/tag/BUG/" target="_blank" >BUG</a>(</span>"PartitionByHotDate cal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>te for " + c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue + " return " +<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; targetPartition);     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; targetPartition; } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (ParseException e) {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Ille<a href="https://www.jb51.cc/tag/gal/" target="_blank" >gal</a>ArgumentException(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> StringBuilder().append("c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue:").append(c<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>umnValue).append(" Please check if the format satisf<a href="https://m.jb51.cc/tag/IE/" target="_blank" >IE</a>d."<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;).toString(),String endValue)  { Integer[] targetPartition </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;try</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> startTime =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; formatter.get().parse(beginValue).getTime();     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> endTime =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; formatter.get().parse(endValue).getTime();     Calendar <a href="https://www.jb51.cc/tag/Now/" target="_blank" >Now</a> </span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; Calendar.getInstance();     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> <a href="https://www.jb51.cc/tag/Now/" target="_blank" >Now</a>Time =<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://www.jb51.cc/tag/Now/" target="_blank" >Now</a>.getTimeInMil<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>s();     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>mitDate = <a href="https://www.jb51.cc/tag/Now/" target="_blank" >Now</a>Time - sLastTime *<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; oneDay;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;long</span> diffDays = (<a href="https://www.jb51.cc/tag/Now/" target="_blank" >Now</a>Time - startTime) / (1000 * 60 * 60 * 24) + 1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span>(diffDays-sLastTime <= 0 || diffDays<0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; ){         Integer [] re </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Integer[1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;];         re[</span>0] = 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         targetPartition </span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; re ;     }</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;{         Integer [] re </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         Integer begin </span>= 0,end = 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         end </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;.cal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>te(beginValue);         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;bo<a href="https://m.jb51.cc/tag/ol/" target="_blank" >ol</a>ean</span> has<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>mit = <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;false</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span>(endTime-<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>mitDate > 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;){             endTime </span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; <a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>mitDate;             has<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>mit </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;true</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;         }         begin </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;this</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;.cal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>te(formatter.get().format(endTime));         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span>(begin == <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span> || end == <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;){             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; re;         }         </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span> (end >=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; begin) {             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> len = end-begin+1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;(has<a href="https://m.jb51.cc/tag/li/" target="_blank" >li</a>mit){                 re </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Integer[len+1<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;];                 re[</span>0] = 0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;                 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> i =0;i<len;i++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;){                     re[i</span>+1]=begin+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;i;                 }             }</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;{                 re </span>= <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; Integer[len];                 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> i=0;i<len;i++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;){                     re[i]</span>=begin+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;i;                 }             }             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; re;         }</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;else</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;{             </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; re;         }     } } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;catch</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; (ParseException e) {     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;throw</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Ille<a href="https://www.jb51.cc/tag/gal/" target="_blank" >gal</a>ArgumentException(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> StringBuilder().append("endValue:").append(endValue).append(" Please check if the format satisf<a href="https://m.jb51.cc/tag/IE/" target="_blank" >IE</a>d."<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;).toString(),e); } </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;return</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; targetPartition;

}

public voID setsPartionDay(String sPartionDay) {
this.sPartionDay = sPartionDay;
}
public voID setDateFormat(String dateFormat) {
this.dateFormat = dateFormat;
}
public String getsLastDay() {
return sLastDay;
}
public voID setsLastDay(String sLastDay) {
this.sLastDay = sLastDay;
}
}

8. 一致性哈希分片

1）首先求出MysqL服务器（节点）的哈希值，并将其配置到0～2^32的圆（continuum）上。

2）为每台MysqL服务器物理节点虚拟出多个虚拟节点，并计算hash值映射到相同的圆上。

3）然后从数据映射到的MysqL服务器虚拟节点的位置开始顺时针查找，将数据保存到找到的第一个MysqL服务器上。如果超过2³²仍然找不到服务器，就会保存到第一台MysqL服务器上。

在rule.xml里面的配置：

ID murmur 0 2 160 节点的权重，没有指定权重的节点默认是1。以propertIEs文件的格式填写，以从0开始到count-1的整数值也就是节点索引为key，以节点权重值为值。所有权重值必须是正整数，否则以1代替用于测试时观察各物理节点与虚拟节点的分布情况，如果指定了这个属性，会把虚拟节点的murmur hash值与物理节点的映射按行输出到这个文件，没有默认值，如果不指定，就不会输出任何东西

对应代码：

import java.io.BufferedReader;
import java.io.ByteArrayinputStream;
import java.io.ByteArrayOutputStream;
import java.io.file;
import java.io.fileinputStream;
import java.io.fileNotFoundException;
import java.io.fileOutputStream;
import java.io.IOException;
import java.io.inputStream;
import java.io.inputStreamReader;
import java.io.OutputStream;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.PropertIEs;
import java.util.sortedMap;
import java.util.TreeMap;

import com.Google.common.hash.HashFunction;
import com.Google.common.hash.Hashing;

import io.mycat.config.model.rule.RuleAlgorithm;
import io.mycat.util.exception.MurmurHashException;

/**

consistancy hash,murmur hash

implemented by Guava

@author wuzhih

*/
public class PartitionByMurmurHash extends AbstractPartitionAlgorithm implements RuleAlgorithm {
private static final int DEFAulT_VIRTUAL_BUCKET_TIMES=160;
private static final int DEFAulT_WEIGHT=1;
private static final Charset DEFAulT_CHARSET=Charset.forname("UTF-8");

private int seed;
private int count;
private int virtualBucketTimes=DEFAulT_VIRTUAL_BUCKET_TIMES;
private Map<Integer,Integer> weightmap=new HashMap<>();
// private String bucketMapPath;

private HashFunction hash;

private SortedMap<Integer,Integer> bucketMap;
@OverrIDe
public voID init() {
try{
bucketMap=new TreeMap<>();
// boolean serializableBucketMap=bucketMapPath!=null && bucketMapPath.length()>0;
// if(serializableBucketMap){
// file bucketMapfile=new file(bucketMapPath);
// if(bucketMapFile.exists() && bucketMapFile.length()>0){
// loadBucketMapfile();
// return;
// }
// }
 generateBucketMap();
// if(serializableBucketMap){
// storeBucketMap();
// }
}catch(Exception e){
throw new MurmurHashException(e);
}
}

private voID generateBucketMap(){
hash=Hashing.murmur3_32(seed);//计算一致性哈希的对象
for(int i=0;i<count;i++){//构造一致性哈希环，用TreeMap表示
StringBuilder hashname=new StringBuilder("SHARD-").append(i);
for(int n=0,shard=virtualBucketTimes*getWeight(i);n<shard;n++){
bucketMap.put(hash.hashUnencodedChars(hashname.append("-NODE-").append(n)).asInt(),i);
}
}
weightmap=null;
}
// private voID storeBucketMap() throws IOException{
// try(OutputStream store=new fileOutputStream(bucketMapPath)){
// PropertIEs props=new PropertIEs();
// for(Map.Entry entry:bucketMap.entrySet()){
// props.setProperty(entry.getKey().toString(),entry.getValue().toString());
// }
// props.store(store,null);
// }
// }
// private voID loadBucketMapfile() throws fileNotFoundException,IOException{
// try(inputStream in=new fileinputStream(bucketMapPath)){
// PropertIEs props=new PropertIEs();
// props.load(in);
// for(Map.Entry entry:props.entrySet()){
// bucketMap.put(Integer.parseInt(entry.getKey().toString()),Integer.parseInt(entry.getValue().toString()));
// }
// }
// }
/**

得到桶的权重，桶就是实际存储数据的DB实例从0开始的桶编号为key，权重为值，权重默认为1。键值必须都是整数@param bucket@return
*/
private int getWeight(int bucket){
Integer w=weightmap.get(bucket);
if(w==null){
w=DEFAulT_WEIGHT;
}
return w;
}
/**创建murmur_hash对象的种子，默认0@param seed
*/
public voID setSeed(int seed){
this.seed=seed;
}
/**节点的数量@param count
*/
public voID setCount(int count) {
this.count = count;
}
/**虚拟节点倍数，virtualBucketTimes*count就是虚拟结点数量@param virtualBucketTimes
*/
public voID setVirtualBucketTimes(int virtualBucketTimes){
this.virtualBucketTimes=virtualBucketTimes;
}
/**节点的权重，没有指定权重的节点默认是1。以propertIEs文件的格式填写，以从0开始到count-1的整数值也就是节点索引为key，以节点权重值为值。所有权重值必须是正整数，否则以1代替@param weightmapPath@throws IOException@throws
*/
public voID setWeightmapfile(String weightmapPath) throws IOException{
PropertIEs props=new PropertIEs();
try(BufferedReader reader=new BufferedReader(new inputStreamReader(this.getClass().getClassLoader().getResourceAsstream(weightmapPath),DEFAulT_CHARSET))){
props.load(reader);
for(Map.Entry entry:props.entrySet()){
int weight=Integer.parseInt(entry.getValue().toString());
weightmap.put(Integer.parseInt(entry.getKey().toString()),weight>0?weight:1);
}
}
}
// /*
// 保存一致性hash的虚拟节点文件路径。
// 如果这个文件不存在或是空文件就按照指定的count,weightmapfile等构造新的MurmurHash数据结构并保存到这个路径的文件里。
// 如果这个文件已存在且不是空文件就加载这个文件里的内容作为MurmurHash数据结构，此时其它参数都忽略。
// 除第一次以外在之后增加节点时可以直接修改这个文件，不过不推荐这么做。如果节点数量变化了，推荐删除这个文件。
// 可以不指定这个路径，不指定路径时不会保存murmur hash
// @param bucketMapPath
// /
// public voID setBucketMapPath(String bucketMapPath){
// this.bucketMapPath=bucketMapPath;
// }
 @OverrIDe
public Integer calculate(String columnValue) {
SortedMap<Integer,Integer> tail = bucketMap.tailMap(hash.hashUnencodedChars(columnValue).asInt());
if (tail.isEmpty()) {
return bucketMap.get(bucketMap.firstKey());
}
return tail.get(tail.firstKey());
}

@OverrIDe
public int getPartitionNum() {
int nPartition = this.count;
return nPartition;
}

private static voID hashtest() throws IOException{
PartitionByMurmurHash hash=new PartitionByMurmurHash();
hash.count=10;//分片数
 hash.init();

 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span>[] bucket=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;[hash.count]; Map</span><Integer,<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a><Integer>> hashed=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> HashMap<><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;(); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> total=1000_0000;<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;//</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;数据量</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> c=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> i=100_0000;i<total+100_0000;i++){<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;//</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;假设分片键从100万开始</span>     c++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> h=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;hash.cal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>te(Integer.toString(i));     bucket[h]</span>++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a></span><Integer> <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;hashed.get(h);     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;if</span>(<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>==<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;){         <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a></span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> Array<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a><><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;();         hashed.put(h,<a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>);     }     <a href="https://m.jb51.cc/tag/List/" target="_blank" >List</a>.add(i); } Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(c</span>+"   "+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;total); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;double</span> d=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; c</span>=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> <a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>x=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(</span>"index    bucket   ratio"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; i:bucket){     d</span>+=i/(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;double</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)total;     c</span>+=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;i;     Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>x</span>+++"  "+i+"   "+(i/(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;double</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)total)); } Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(d</span>+"  "+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;c); Propert<a href="https://m.jb51.cc/tag/IE/" target="_blank" >IE</a>s props</span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; Propert<a href="https://m.jb51.cc/tag/IE/" target="_blank" >IE</a>s(); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;(Map.Entry entry:hash.bucketMap.entrySet()){     props.setProperty(entry.getKey().toString(),entry.getValue().toString()); } ByteArrayOutputStream out</span>=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; ByteArrayOutputStream(); props.store(out,</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;n<a href="https://m.jb51.cc/tag/ul/" target="_blank" >ul</a>l</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;); props.clear(); props.load(</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; ByteArray<a href="https://m.jb51.cc/tag/input/" target="_blank" >input</a>Stream(out.toByteArray())); Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(props); Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(</span>"****************************************************"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;);

// rehashTest(hashed.get(0));
 }
private static voID rehashTest(List partition){
PartitionByMurmurHash hash=new PartitionByMurmurHash();
hash.count=12;//分片数
 hash.init();

 </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span>[] bucket=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;new</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;[hash.count]; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> total=partition.size();<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;//</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;数据量</span> <span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> c=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> i:partition){<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;//</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #008000"&gt;假设分片键从100万开始</span>     c++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;;     </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> h=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;hash.cal<a href="https://www.jb51.cc/tag/cula/" target="_blank" >cula</a>te(Integer.toString(i));     bucket[h]</span>++<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; } Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(c</span>+"   "+<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;total); c</span>=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span> <a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>x=0<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;; Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(</span>"index    bucket   ratio"<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;); </span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;for</span>(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;int</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt; i:bucket){     c</span>+=<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;i;     Sy<a href="https://www.jb51.cc/tag/stem/" target="_blank" >stem</a>.out.println(<a href="https://m.jb51.cc/tag/ID/" target="_blank" >ID</a>x</span>+++"  "+i+"   "+(i/(<span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #0000ff"&gt;double</span><span https://m.jb51.cc/tag/color/" target="_blank" >color</a>: #000000"&gt;)total)); }

}
public static voID main(String[] args) throws IOException {
hashtest();
}
}

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